It is quite good in general, but the target audience is unclear. If you already know Rust, the first third feels redundant. If you do not, the material is often too simplistic to build a solid understanding. At the same time, a solid knowledge of Bitcoin is required to have a genuine interest in the book at all.
What I miss is a clearer middle ground between a brief introduction and a “let’s dive in” approach. Some concepts would benefit from being introduced earlier or later when they first appear. In addition, accompanying video walkthrough and/or publishing the code with extensive comments would significantly improve accessibility.
That said, this is a difficult topic to cover in book form, and overall it is handled quite well.